The present invention relates to a cylinder cleaning apparatus for a printing press which presses a cleaning web against the circumferential surface of a cylinder, e.g., a printing cylinder or a roller, and wipes the circumferential surface of the cylinder with the cleaning web.
Various types of printing presses, e.g., an offset press and an intaglio printing press, have printing cylinders, e.g., a plate cylinder, a blanket cylinder, an impression cylinder, and a transfer cylinder, and rollers, e.g., a form roller and a vibrating roller, all of which serve as cylinders. During printing, foreign matters, e.g., ink dust and paper dust attach to the circumferential surfaces of these printing cylinders and rollers to degrade the quality of printed matter. Hence, the printing press is provided with a cylinder cleaning apparatus for removing the foreign matters by wiping the circumferential surfaces of the cylinders, e.g., printing cylinders and rollers with a cleaning web constituted by roll paper, an unwoven fabric, a roll cloth, or an ordinary cloth.
More specifically, U.S. Pat. No. 4,344,361 and Japanese Utility Model Laid-Open No. 3-90943 disclose examples of a cylinder cleaning apparatus of this type. The cylinder cleaning apparatus disclosed in the former gazette has a rubber bladder which is inflatable with compressed air. The bladder is inflated to press a cleaning web engaged with the bladder against a blanket cylinder, thereby cleaning the cylinder. The cleaning web is pressed against or separated from the cylinder by inflation and deflation of the bladder. The cylinder cleaning apparatus disclosed in the latter gazette has an expandable member which is expanded with compressed air. After the expandable member is expanded, a unit having the expandable member and a cleaning web mounted thereon is moved by air cylinders toward the blanket cylinder, and the cleaning web engaged with the expandable member is pressed against the blanket cylinder, thereby cleaning the blanket cylinder. The cleaning web is pressed against or separated from the cylinder by moving the unit forward and backward by activating the air cylinders.
However, since any one of the cylinder cleaning apparatuses of the prior art techniques described above uses an expandable member, it requires a sealing structure so that the compressed air will not leak when this expandable member is expanded, resulting in a complicated, expensive cylinder cleaning apparatus. When the expandable member is worn or bursts, a cumbersome repair work must be performed.